Process of manufacturing viscose



Pastas Jul 22; 1924.

Nrr is r CHARLES A. HUTTINGER, OF LAKEWOOD,

SILK COMPANY, OF CLEVELAND,

E0, ASSIGNOR TO THE ACME ARTIFICIAL OHIO, A CORPORATION OF OHIO.

rnocnss or MANUFACTURING vrscosn.

. No Drawing.

tions.

The subject matter of this application has been divided out of my pending application,

Serial No. 303,776, filed June 12, 1919.

My invention relates to processes of manufacturing viscose. The purpose of the invention isto compound a viscose solution effective in, producing lustrous threads of '20. the character described and claimed in my U. S.'Let'ters Patent No. 1,425,654. By the improvements herein described and claimed I amenabled to make a viscose solution suitable for producing a lustrous thread of the as necessary qualities as regards its luster,

strength and elasticity, without the necessity of using any free acid in the precipitating bath and wlthout the necessit ofheating the latter above the usual wor ing room temperature. I accomplish -this object-both by the proportions of the ingredients which I utilize inmaking my viscose solution and in my methods of compounding same.

The following description sets forth in detail certain steps illustrating the method of carrying out my invention, such described steps constituting, however, but one of the various ways in which} the principle of the invention may be utilized.

In carrying out my improved process, I cut up. a certain amount of wood. pulp, one kilogram for'instance, and then saturate the same with sodium hydroxide. The saturation is efi'ected by a water solution of sodium hydroxide of substantially 1.17 specific grave ity. The amcuntof sodium hydroxide which I use, for the stated amount of wood pulp,

is substantially. 515 grams, andthe amount of water utilized in making a solution of the specific gravity noted is substantially 2918 grams, which is a 15 er: cent solution of sodium hydroxide. T e treatment of the wood pulp with this sodium hydroxide solution contmues' for from one to five hours, preferably about one and a half 'hours. I

A. HUT

Application filed June 28, 1922. Serial No. 571,567.

then subject the wood pulp. and sodium hy-- droxide water solution to great pressure, by means of a hydraulic press when treating comparatively large amounts, or by means of a screw press for small quantities, so that the material remaining on the press, i. e., the alkali cellulose, amounts to substantially 3 kilograms, when using the various amounts.

stated. Of these 3 kilograms, substantially 13.5 per cent is alkali, including the small amount which is free, as well as that which has combined, substantially 27 per cent'is cellulose, and the remainder, 59.5 per cent, is Water. I grind u these 3 kilograms of alkali cellulose remaining on the press, this alkali cellulose being a crumby material. I then subject the same to the action .of substantially 325grams of carbon bisulphide for about two hours. substantiall fifteen (15) times the amount of wood pu poriginally utilized, or, as exactlyas I have determined, 15.023 kilograms of water, the mixture being allowed I then add water of to stand for substantially three hours. This comparatively large amount of water'will dissolve some of the small amount of free sodium hydroxide in the alkali cellulose-carbon bisulphide mixture, so that the water is slightly alkaline. during an aging period of about five days.

The viscose solutioncompounded as above The resultant mixture is filtered v can be spun into a lustrous thread, having all the desirable qualities in the proper de-' gree, in a. precipitating bath containing nofree acid and used at substantially the .usual working room temperature, as described and claimed in said Patent No. 1,425,654. My explanation of my ability to thus secure a satisfactory thread, under these conditions,-

is that my method of compounding the vis-' cose solution results in a saturation of the wood pulp with sodium hydroxide without,

there bein present in the solution there- I after a hig ercentage of free sodium hydroxide, whic free sodium hydroxide must necessarily be neutralized out of the solution to leave the cellulose. for the thread.

This neutralizatign'has been effectedheretofore by the acid used. Thus, the lack of surplus hydroxide in my method obviates the necessity of free acid for neutralizing such sodium hydroxide. I

WhatI claim is: I 1.. In processes of manufacturing viscose, the steps which-consist, in saturatmg wood pulp with a water solution of sodium. hydroxide of substantially a specific gravity of 1.17, and subjecting the mixture of said Wood pulp and said solution to great pressure so that the-resultant alkali cellulose will equal substantially three times the amount of Wood ulp utilized, and of which the cellulose will comprise substantially 27 per cent; adding carbon bisulphide to the alkali cellulose of substantially one-third the amount of the original wood pulp utilized; adding a comparatively large amount of water; and filtering.

2. ln processes of manufacturing viscose, the steps which consist, in saturatmg wood pulp with a water solution of sodium hydroxide of substantially a specific gravity of 1.17, and subjecting the mixture of said wood pulp and said solution to great pressure so that the resultant alkali cellulose will equal substantiall three times the amount of Wood pulp utilized, and of which the ce-l lulose will comprise substantially 27 per cent; grindin said alkali cellulose; adding carbon bisulp ide thereto of substantially isoaioi stantially 3 kilograms, of which 13.5 per cent is combined and free sodium hydroxide and 27 per cent is cellulose; grinding up the resultant alkali cellulose, and then subjecting the same for substantially two'hours to the action of 325 grams of carbon bisulphide; adding substantially 15 kilograms of water; and filtering and aging for substantially 5 days. I

Signed by me, this 6th day of June, 1922.

CHARLES A. HUTTINGER. 

